Stay-bolt for boilers.



B. E. D. STAFFORD I E. I. DODDS. STAY B OLTFO'R BOILERS.

APPLICATION FILED MAR.27,19I5.

1,261,989. Pam-ed 001;. 17, 1916.

WIWIIIIIIIIIII J ff IIIII l UNITED sTATEs PATENT oEEroE.

BENJAMIN E. D. STAFFORD AND ETHANiI. DODDS, k011" PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.v

STAY-BOLT Fon BOILEEs.,

Specification of Letters Patent.

Patented Oct. 17, 1916.

Application filed March 27, 1915. Serial No. 17,522.

To all whom t may concern:

Be it known that we, BEvJAMIN E. D.- STArroRD and ETHAN I. DoDDs, citizens of the United States, and residents of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new` and useful Improvements in Stay-Bolts for Boilers; and we do hereby declare the following tok be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and'use the same.

Our invention relates to an improvement in stay bolts for boilers, the object being to provide a yielding coupling for one end of the bolt, whereby the latter will be free to follow the movements of the fire box sheet of the boiler without buckling or unduly straining either of the sheets. l

A further object is to provide a construcv tion designed to prevent scale getting between the bolt and the part of the bearing directly supporting the bolt head.

Vith these objects in view our invention' consists in the parts and combinations of parts as will be hereinafter more fully explained.

Qur invention further consists in the details of construction as will be more fully explained and pointed out in the claims. Y l n In the accompanying drawings, Figure 1 is a view partly in section and partly in elevation of our improvement, and Figs. 2 to 5 inclusive are views in section of modifications.

l represents a rigid bolt one end of which is adapted for attachment to the inner sheet Q of the fire box or boiler, and the other end threaded for the attachment ofthe head 3, the outer surface of which is spherical in shape. 4 is the sleeve, threaded externally at its outer end for attachment to the outer sheet 5, and provided internally with a curved seat 6 on which the head 3 of the bolt 1 rests, and which is shaped to conform to the shape of the head. v

The sleeve 4 is provided at its inner end with an extension 7 which is circumferentially fluted as shown, soas to yield or give and act as a spring under longitudinal/or lateral stresses to which the bolt maybe subjected. The sleeve so constructed is preferably heat treated and cooled in oil so that the luted or spring section thereof will retain its elasticity when exposed to the high temperatures to which they are subjected in use.-

The bolt 1 is provided at the inner free end of the spring extension of the sleeve, with a peripheral shoulder 8, having an inclined face against which the inwardly turned edge of the spring extension 7 abuts, the edge of said extension being beveled to conform to the face of the shoulder 8, so as to form a tight joint with said shoulder and thus prevent the passage of scale into the space between the bolt and the sleeve, above said shoulder.

The head 3 and shoulder S of the bolt normally rest on or against their respective seats, so that a pulling strain on the bolt falls solely on the head 3 and seat 6 whichr are rigid and unyielding, whereas a pushing stress, or lateral movement, falls o n the free end of the spring extension which gives or yields to a limited 'extent and permits the bolt to move outwardly.

The vouter open endl of the sleeve 4' is covered by a cap 9 whichl may haveV a central opening for the escape of steam or water in the event the bolt should be broken adjacents its head, which is the point where they usually give way, the telltale 1l in the end of the bolt permitting the steam or water toy escape into the sleeve. v

In the construction shown in Fig. 2, the inner end of the spring extension is secured by threads 12 to the shank of the bolt, and in Fig. 8 it is similarly secured, and the head of the bolt is made integral with the bolt shank.

In Fig. 4: the bolt head 3a is provided with an extension 13 having an outwardly turned outer edge 14 which rests against the inner free end of the spring extension 7a, and in the construction shown in Fig. 5 the` extension 13a from the head 3a is also provided with an outwardly turned outer edge 14a to bear against the inner edge of the extension 7a, and the extension itself is also tinted, so that with this construction, we get the combined spring action of the extensionr of the sleeve and also that of the extension fromA thehead. I'

Vith each of the constructions above referred to, it will be apparent that pulling stresses on the bolt simplyvseat the head solforced l'outwardly due tov movements of the inner sheet, the shoulder movable with thel bolt, bearing against the inner end of the spring extension ofthe sleeve, compresses the latter sutliciently to compensate for the movement, and when the stress is relieved the spring action of the fiuted extension forces or draws'the bolt back to its normal position.

' pansion of the iuted extension, or the move-r ment of the k'bolt within the same.

jacket assists in preventing the passage of `scale between the bolt and sleeve and also quired by the scope of the appended claims.

By means of the iiuted extension toithe sleeve, suilicient elasticity may be available `to absorb or take care of all necessary longitudinal lateral and vbratory movements to which the bolt may be subjected, due to elongation of the bolt itself,` or to longitudinal and ,lateral movement of the bolt due to outward or lateral movement or buckling action of the inner sheet and provides in effect for universal movementy of the end of the bolt within the coupling.

If desired the fluted extension of the sleeve may be covered by the thin sheet metal jacket' l5, shown in Fig. 1. This jacket embraces the fiuted portion ofthe sleeve and also the bolt shank in rear of the iuted extension. It may be secured atv its outer end to the sleeve, but is free at all other points so as not to interfere with the YJfree contraction or eX- prevents its lodgment within the outer grooves ofthefluted ortion. If desired the outer grooves of the uted part may be lled with a grease whichfwill not melt below 800, and which will be retained in place by the gjacket.k It is evident that many slight changes mightV be resorted to in the relative arrangement of parts shown and described without departingfrom the spirit and scope of our invention. Hence we would have it understood that we do not wish to conine ourselves to the exact construction and arrangement of parts shown and described except as reboiler sheet and having a spring extension at Y Copies of this patent may be vobtained for This boiler sheet and having a spring extension at its inner end,- and a curved seat adjacent its outer end, and a bolt having a head to engage sald seat and also having means to enl gage the free end of the spring extension of the sleeve.

- 4. In stay bolt construction, the combination of a sleeve threaded for attachment to a boilerjsheet, and provided at its inner end with an integral spring extension, and with an internal seat for the head of a bolt, a bolt having ahead to rest on said seat and also .provided with means to engage the inner free edge of the spring extension.

5. In stay bolt construction, the combination of a sleeve threaded for attachment to a boiler. sheet and provided at its inner end with a yielding extension and a bolt having engagement with the free end of said extension whereby the bolt will be yieldingly restrained against outward movement.

6. In stay bolt construction, the combination of a sleeve having, an internal curved seat and an inward extension the latter being yielding, and a bolt having a head to engage said seat and also provided with a shoulder to engage the free end of the yielding extension. Y

7 yIn stay bolt construction, the combination of a sleeve having an internal curvedL seat and an inward extension, the latter being yielding, and a bolt having a detachable head to rest on the curved seat and also provided with a shoulder to engage the inner free end of the yielding extension.

8. In ,stay bolt construction, the combination of a sleeve threaded for attachmentto a boiler sheet and having a luted yielding extension at its innerv end,"a bolt having engagement with the free end of said extension whereby the bolt will be yieldingly restrained against outward movement and a sheet metal jacket covering said fluted extension.

In testimony whereof, we have signed this specification in the presencefof two subscribing witnesses.

BENJAMIN E. D. sTAFFoRD. ETHAN I. Donne.

' lVitIesses:

F. H. ALLIsoN, EDWIN S. RYGE.

five cents each, by addressing the Commissioner of Patents, washington, D. c. 

